Objective:To investigate the effects of PTEN down-regulation on learning and memory abilities after global cerebral ischemia in rats.Methods:The experimental therapy model after global cerebral ischemia and reperfusion was established by four-vessel occlusion(4VO)after 2 days of pshRNApten injected into the hippocampal cell layer of SD rats.The behavioral effects were measured with somatosensory evoked potential(SEP)and computerized shuttle-training case respectively.The expression of CREB was analyzed by RT-PCR and immunohistochemistry method.Results:Compared with the pshGFP group

the AAR(active avoiding reaction)with computerized shuttle-training case in the pshRNApten group raise markedly in the first and second week.Results of somatosensory evoked potential(SEP)in pshRNApten group showed that the latency period of P1 wave shorten markedly and P1-N1 amplitude increase significantly after ischemia and reperfusion(P<0.05).The expression of rat hippocampal CREB with immunohistoch-emieal method and RT-PCR was obviously increased in pshRNApten treatment groups compared to pshGFP groups.Conclusion:Downregulating PTEN could enhance learning and memory ability and improve neuronal function

which changes were correlated with the increase of CREB.